The low-valent iron complex Bu(4)N[Fe(CO)(3)(NO)] (TBAFe) catalyzes the allylic C-C-bond activation of electron-poor vinyl cyclopropanes to generate synthetically useful a1,a3,d5-synthons which are prone to undergo multiple consecutive reactions. The versatility of this approach is demonstrated by a traceless allylic substitution and a formal [3 + 2] cycloaddition to give either functionalized acyclic products or densely substituted cyclopentanes and pyrrolidines in high yields and regioselectivities.

A new concise construction of trans-clerodane diterpenoids is reported in which oxacyclic and trans-hydronaphthalene fragments are coupled, and the critical C9-quaternary carbon stereocenter formed stereoselectively, by 1,6-addition of a tertiary cuprate or a tertiary carbon radical to β-vinylbutenolide. This strategy is specifically illustrated by total syntheses of (-)-solidagolactone (4), (-)-16-hydroxycleroda-3,13-dien-15,16-olide (5, PL3), and (-)-annonene (6).

Iron at the crossroads: A remarkable mechanistic dichotomy in iron‐catalyzed allylic substition increases not only the scope of regioselective allylic alkylation but could also herald the development of asymmetric allylic substitution (see Scheme, MTBE=methyl tert‐butyl ether). Depending on the ligand used, either a σ‐ or a π‐allyl mechanism is observed.

Nowadays demand for selective, energy-efficient, and sustainable chemical transformations has spurred an increasing interest in the development of "sustainable metal catalysis". This expression defines a type of catalytic transformation in which non-toxic, readily available and inexpensive, stable metal complexes are used for catalysis. The increasing prices for energy and noble metals, which are commonly used for catalysis, represent an economical and ecological dilemma. If the price for a catalyst exceeds the savings on the energy side an industrial application does not make sense. As a consequence of this dilemma, chemists are looking for exit stra-

The evolution of a convergent fragment-coupling strategy for the enantioselective total synthesis of trans-clerodane diterpenoids is described. The key bond construction is accomplished by 1,6-addition of a trans-decalin tertiary radical with 4-vinylfuran-2-one. The tertiary radical is optimally generated from the hemioxalate salt of the corresponding tertiary alcohol upon activation by visible light and an Ir(III) photoredox catalyst. The enantioselective total synthesis of trans-clerodane diterpenoid 1 reported here was accomplished in seven steps from 3-methyl-2-cyclohexenone. The synthetic strategy described in this report allows a number of trans-clerodane diterpenoids to be synthesized in enantioselective fashion by synthetic sequences of 10 steps or less. This study illustrates a powerful tactic in organic synthesis in which a structurally complex target structure is disconnected at a quaternary carbon stereocenter to fragments of comparable complexity, which are united in the synthetic pathway by conjugate addition of a nucleophilic tertiary radical to a fragment harboring an electron-deficient C-C double bond.